1. Field of the Invention
This invention relates generally to audio processing and more particularly to a system capable of identifying and removing noise disturbances from an audio signal.
2. Description of the Related Art
Voice input systems are typically designed as a microphone worn near the mouth of the speaker where the microphone is tethered to a headset. Since this imposes a physical restraint on the user, i.e., having to wear the headset, users will typically use the headset for only a substantial dictation and rely on keyboard typing for relatively brief input and computer commands in order to avoid wearing the headset.
Video game consoles have become a commonplace item in the home. The video game manufacturers are constantly striving to provide a more realistic experience for the user and to expand the limitations of gaming, e.g., on line applications. For example, the ability to communicate with additional players in a room having a number of noises being generated, or even for users to send and receive audio signals when playing on-line games against each other where background noises and noise from the game itself interferes with this communication, has so far prevented the ability for clear and effective player to player communication in real time. These same obstacles have prevented the ability of the player to provide voice commands that are delivered to the video game console. Here again, the background noise, game noise and room reverberations all interfere with the audio signal from the player.
As users are not so inclined to wear a headset, one alternative to the headset is the use of a microphone to capture the sound. However, shortcomings with the microphone systems currently on the market today is the inability to detect and remove noise disturbances from the audio signal. It should be appreciated that where the microphone is incorporated into an input device, e.g., a video game controller, noise disturbances arise from various kinds of mechanical activities on the input device. For example, with a game controller the noise disturbance can result from button pushes, joystick clicks, finger taps, table hits, controller vibration, surface friction, etc.
Due to the unique nature of close distances between a microphone sensor and various type mechanical input devices mounted on an input device, such as a game controller, the sharp disturbances occur when the microphone picks up and amplifies nearside mechanical noises, e.g. pushing game button, clicking joystick, hitting table, tapping controller surface, force feedback, vibration, etc. Unlike the classical problem of removing impulsive noises resulted from analog signal transmission, here the mechanical disturbance has a much longer and more dynamic shelf life. The disturbance's audible duration may range from a sharp steep impulse less than 50 ms (such as joystick click) all the way up to the whole lifetime of an utterance (such as talking while touching the surface of haptic device). Besides, some percussive human sounds, such as yelling, stop-consonants, etc., further blur the line drawn between the wanted “normal sound” (also referred to as target sound) and mechanical disturbance (also referred to as noise disturbance). Furthermore, the restoration of the corrupted audio signal must attain an efficient separation of mechanical noise from the audio signal.
As a result, there is a need to solve the problems of the prior art to provide a microphone used in conjunction with an input device in order to detect and remove the noise disturbances generated in the near field.